Controle de crestamento bacteriano comum (Xanthomonas axonopodis pv. phaseoli) e alterações bioquímicas em feijoeiro induzidas por Pycnoporus sanguineus

Abstract

Bean (Phaseolus vulgaris) is among one of the main Brazilian crops and can be affected by several diseases, such as common bacterial blight caused by Xanthomonas axonopodis pv. phaseoli. The study of this interaction can contribute to development of alternative methods to control this disease. The aim of this work was to verify the antimicrobial and resistance induction activities of Pycnoporus sanguineus extracts for the control of this bean disease. The in vitro assays was conducted at the Laboratory of Plant of the State University of West of Paraná (UNIOESTE) - Campus of Marechal Cândido Rondon - PR and were used aqueous extracts from basidiocarp, mycelium and culture filtrate of P. sanguineus in concentrations of 1, 5, 10, 15 and 20%, with water, acibenzolar-S-methyl (ASM - 125 mg a.i. L-1) and antibiotic (oxytetracycline 22.5 mg L-1 + streptomycin 225 mg L-1) as control treatments. For in vivo assays were evaluated disease severity and the activities of peroxidase, polyphenol oxidase, β-1,3 glucanase and phenylalanine ammonia-lyase, using extracts of mycelium, basidiocarp and culture filtrate of P. sanguineus at 5 and 10%, these tests being conducted in greenhouses in the area belonging to the Complex Biological Control and Protected Cultivation Mario Cesar Lopes of UNIOESTE, Campus of Marechal Cândido Rondon. In vitro was verified antibacterial activity only for culture filtrate in concentrations up 15% and for all concentrations of basidiocarp extract. In vivo the results indicated the potential of basidiocarps extracts from P. sanguineus for the control of Xanthomonas axonopodis pv. phaseoli in bean, which can occur either by direct antimicrobial activity and resistance induction involving the activation of enzymes studied